Interesting facts

Personality traits change throughout a person’s life

For a long time, professional psychology was dominated by the belief that personality traits are something stable and almost unchanging, as if they are formed in childhood, consolidated by the beginning of adulthood, and then remain virtually unchanged. For example, the phrase “stay true to yourself” reflects the deep‑seated idea that there is some fixed inner essence of a person. Even when people deliberately work on themselves, they often interpret this not as a real change in their personality, but as “revealing their true self” or getting rid of bad habits. A new study shows that this picture does not fully reflect reality.

The scientists set themselves two tasks:

to find out how much personality traits actually change compared to other life variables (such as income, health, or life satisfaction);
to compare these real changes with how ordinary people imagine them.

To do this, they used a two‑stage approach. In the first stage, 887 adult residents of the United States were asked to rate, on an 11‑point scale (from “does not change at all” to “changes very much”), how much, in their opinion, 25 different characteristics vary between the ages of 15 and 90. The list included five basic personality traits (the so‑called “Big Five”: extraversion, agreeableness, conscientiousness, neuroticism, and openness to experience), as well as other parameters — income level, physical health, self‑esteem, frequency of social contacts, and others.

In the second stage, the researchers turned to data sets from eight large‑scale longitudinal studies, which together covered 166,971 people from the USA, Germany, Australia, and the Netherlands. These projects tracked the same individuals over the years, recording the dynamics of their personality traits. To separate real shifts from statistical noise, the experts applied a complex mathematical model — hierarchical cross‑classified random effects accounting for age, period, and cohort (HAPC‑CCREM). This approach made it possible to measure two types of changes: net change (the overall shift from 15 to 90 years) and cumulative change, which takes into account all fluctuations throughout a person’s life, even if they ultimately return to their original level.

The results were revealing. The traits of the “Big Five” changed no less, and often more, than the parameters that are generally considered more flexible, such as life satisfaction, income, or health status. Thus, conscientiousness (the tendency to be attentive, responsible, and diligent) undergoes noticeable transformation throughout life: its level in a teenager and in a 90‑year‑old person can differ significantly. Among the 32 measured life variables, extraversion and openness to experience ranked among the top ten in terms of the magnitude of overall decline over the lifespan, while conscientiousness took fifth place in terms of total variability, meaning it turned out to be one of the most dynamic personality traits.

The gap between people’s perceptions and reality turned out to be particularly striking. If respondents were wrong in their predictions about their own health in 29–43 % of cases, then in assessing changes in personality traits they systematically underestimated the scale of the changes: in 90 % of cases regarding annual changes, and in 100 % of cases regarding changes over a lifetime. In other words, people almost always considered their personality to be much more stable than it actually was.

The scientific work reflects average trends for large groups and does not reveal how personality dynamics unfold in individual people. A more comprehensive understanding could be achieved by combining the macro level (general trends) with the micro level (individual trajectories). Nevertheless, the data obtained allow us to propose a more realistic view that a person’s personality can change over the course of their life, although these changes usually occur gradually.

Published

August, 2026

Updated

August 2026